The present invention relates to swimming pool cleaners and, more particularly, to automatic swimming pool cleaners driven by the flow of water therethrough for purposes of cleaning. Still more particularly, this invention relates to swimming pool pressure cleaners (as opposed to suction-type cleaners) of the type powered by the flow of water pumped by remote pumps into and through the pool cleaners.
Automatic swimming pool cleaners of the type that move about the underwater surfaces of a swimming pool are driven by many different kinds of systems. A variety of different pool cleaner drive devices in one way or another harness the flow of water, as it is drawn or pushed through the pool cleaner by the pumping action of a remote pump for debris collection purposes, to create forward pool cleaner movement. Some of the many kinds of water-driven automatic pool cleaners are those driven in various ways by turbines, which translate water movement into rotational motion. Wheel rotation by linkage to a turbine or other drive mechanism causes propulsion in such prior art devices. Various problems and shortcoming exist in such prior devices.
Among the problems and shortcomings not adequately addressed are failures of certain kinds of cleaners to provide complete cleaning coverage. Obtaining complete coverage is particularly difficult or problematic for swimming pools having certain kinds of surfaces, surface shapes or obstacles. Complete coverage and satisfactory cleaning are difficult to obtain when the pumping pressure generated by the remote pump is weak, such that the driving force of a pool cleaner is seriously diminished. Various automatic pool cleaners of the prior art have insufficient speed and strength of movement, and this creates and acerbates problems of weak cleaning ability.
Some problems, failures or difficulties occur when pool cleaners get hung up or caught at an area where its driving wheels are unable to contact the underwater pool surfaces, or are at least unable to engage such surfaces with sufficient traction to allow movement of the pool cleaner. For some cleaners of the prior art, steering (that is, the motions taken by pool cleaners in order to change directions) can be problematic, particularly on certain kinds of surfaces and when speed is low and the steering and propulsion forces that are generated are low.
Certain of these problems are particularly difficult with respect to so-called xe2x80x9cpressure cleanersxe2x80x9dxe2x80x94i.e., those pool cleaners the movement of which is motivated by the flow of water pumped to the pool cleaner from a remote pump, as opposed to the more common suction cleaners, through which water is sucked by a remote pump. One problem particularly seen with respect to pressure cleaners is difficulty in obtaining reliable steering for complete coverage of the underwater surfaces of a pool. Steering of certain pressure cleaners of the prior art is typically by external means.
A brief description of certain swimming pool pressure cleaners of the prior art will be helpful. Such pool cleaner includes the pool cleaner unit itself at the end of a water-supply hose and a separate box-like control unit along the hose and spaced from the pool cleaner unit itself by a distance on the order of ten feet or so. The pool cleaner unit itself is a wheeled device which includes a turbine for driving the wheels, but does not have any steering apparatus incorporated with it. The box-like control unit, which has a second turbine and a sequencing device, periodically shuts off the flow of water to the pool cleaner unit itself and at the same time opens up an orifice which shoots a jet of water from the control unit such that the control unit, acting through the hose, in effect drags the pool cleaner unit into a different orientation and/or position, after which the flow to the pool cleaner unit is reestablished and the jet of water from the control unit is stopped.
In such prior pressure cleaning apparatus, water flow to the pool cleaner unit itself, which has already been used to move a turbine in the control unit, is split into two streamsxe2x80x94one for driving the turbine in the pool cleaner unit and one to establish a venturi action for drawing water and debris into a flow path leading to a filter bag or the like. Due to the prior usage and flow splitting, sometimes including an additional separate flow for the purpose of placing or keeping dirt near the pool cleaner in suspension, power for pool cleaner movement is lost and, perhaps more importantly, flow for creating the venturi is limited.
As a result, the venturi jet(s) used in such prior systems are made very smallxe2x80x94sometimes as low as about 0.100-0.160 inch in diameterxe2x80x94allow development of high linear flow velocities of water from the venturi jet(s), despite the low flow volume. Low flow volumes and very localized venturi effects limit pool cleaning effectiveness in such prior pool cleaners. One specific result of the low flow volumes from the venturi jet(s) is that the opening for inflow of water and debris is more limited in size than is desirable. Thus, the inflow of debris and the size of the debris which can be collected are more limited than is desirable.
Other problems and shortcomings are associated with such apparatus. Control of the pool cleaner at best tends to be rather ineffective, resulting in ineffective coverage of the surfaces of a pool. Furthermore, because of division of water flow from the hose, the water available to operate the principal turbine of the apparatus is reduced, and this in turn reduces the strength of travel of the pool cleaner unit and detracts from its cleaning power.
While various advances have been made in the field of automatic swimming pool cleaners, including pressure cleaners, as of this writing there remains a need for an pressure cleaner for swimming pools which is internally self-steerable. More generally, there is a need for automatic pool cleaners with improved functionality to address the problems referred to above.
It is an object of this invention to provide an improved swimming pool cleaner pressure cleaner of the automatic water-driven type which overcomes some of the problems and shortcomings of the prior art.
Another object of this invention is to provide an improved water-driven swimming pool pressure cleaner having an internal steering mechanism.
Another object of the invention is to provide an improved water-driven swimming pool pressure cleaner giving excellent coverage and cleaning of underwater pool surfaces, including hard-to-reach areas.
Another object is to provide an improved water-driven swimming pool pressure cleaner with highly reliable self-steering.
Another object of the invention is to provide an improved water-driven swimming pool pressure cleaner which has excellent traction in a variety of situations.
Another object of this invention is to provide an improved water-driven swimming pool pressure cleaner able to utilize a greater portion of flow from the remote pump, and a greater portion of the power of the flow from the remote pump, to create venturi action for picking up debris.
Another object of this invention is to provide an improved water-driven swimming pool pressure cleaner with larger inflow openings for water and debris and an increased venturi effect in drawing of unwanted debris into a collector.
Another object of this invention is to provide an improved water-driven swimming pool pressure cleaner which can operate effectively at lower pressures than many pressure cleaners of the prior art.
Still another object of the invention is to provide an improved water-driven swimming pool pressure cleaner which has excellent ability to traverse pool surfaces of different types and hard-to-reach pool areas.
Another object of the invention is to provide an improved water-driven swimming pool pressure cleaner which generates good driving power even when used with pool pumping systems generating low pumping pressures.
Another object of the invention is to provide an improved water-driven swimming pool pressure cleaner which resists any tendency to become hung up and is capable of extracting itself from situations in which there is a lack of traction.
Still another object is to provide an improved water-driven swimming pool pressure cleaner with excellent speed and steering (direction-changing) capabilities.
These and other objects of the invention will be apparent from the following descriptions and from the drawings.
This invention is an improved swimming pool pressure cleaner of the type motivated by water flow through it to move along a pool surface to be cleaned. The invention, including in its preferred embodiments, overcomes various problems and shortcomings of the prior art, including those referred to above. The invention is a pressure cleaner for swimming pools which incorporates within itself apparatus which provides self-steering.
The swimming pool pressure cleaner of this invention provides many important advantages, including the following: compactness in a pressure cleaner with steering by virtue of the inclusion of steering apparatus in a single structure; excellent coverage of underwater surfaces, highly-reliable self-steering; improved take-up of debris, a larger inflow opening for debris; better utilization of water flow, for purposes of propulsion, steering and take-up of debris; effective pool cleaner operation at low pressure; excellent traction; ability to avoid and/or escape situations involving hang-up of the pool cleaner; and excellent speed and power.
The swimming pool pressure cleaner is a pressure cleaner of the type including a body, wheels rotatably mounted to the body, a turbine housing having a water-flow chamber formed by a chamber wall and having an inlet and an outlet, a turbine rotor rotatably mounted in the chamber and having vanes, a drive member secured to the rotor and a drive train from the drive member to drive the wheels on underwater pool surfaces, a venturi jet and a water conduit to feed water to the venturi jet from a hose.
In the inventive pool cleaner, the turbine inlet is supported in close proximity to the pool surface and the venturi jet is located at the turbine inlet, oriented to direct water into the turbine inletxe2x80x94to both rotate the turbine and cause water and debris to flow from the pool past the venturi jet and into the inlet, by means of venturi action. The pool cleaner also includes a steering mechanism secured to the body and having a movable part which periodically interrupts the synchronous rotation of the wheels on the pool surface, thereby causing changes in the direction of pool cleaner travel.
The steering mechanism in the pool cleaner of this invention is sometimes referred to as xe2x80x9cinternal.xe2x80x9d The pool cleaners of this invention are compared to pressure cleaners having an additional apparatus which may be said to provide some xe2x80x9csteeringxe2x80x9d for a pool cleaner. But such additional apparatus is separate from the pool cleaner and linked to it only by a length of flexible hose by which the additional apparatus pulls the pool cleaner unit in various directions. With this in mind, the term xe2x80x9cinternalxe2x80x9d as used herein means xe2x80x9caffixed thereto as a part thereof xe2x80x9d Thus, the term xe2x80x9cinternalxe2x80x9d does not carry with it the idea that the steering mechanism is enclosed to any extent.
In highly preferred embodiments, the steering mechanism includes: a cam having portions of greater and lesser radii which is rotatably secured to the body and driven by the rotor through reduction gearing; and linkage from the cam to a wheel to periodically interrupt synchronous rotation of the wheels on the pool surface.
In more detail, the device of this invention includes: a body having front, rear and opposite sides; a set of two wheels rotatably mounted to the body, one on each side; a turbine housing secured to the body and having a water-flow chamber formed by a chamber wall, the chamber having an inlet and an outlet, the inlet supported in close proximity to the pool surface; a turbine rotor rotatably mounted in the chamber, the rotor having vanes, one or more venturi jets secured to the body and oriented to direct water into the inlet to rotate the turbine and cause, by virtue of the venturi action, a flow of water and debris from the pool into the inlet; one or more water conduits to transmit water from a hose to the one or more venturi jets; a drive member secured to the rotor and rotatable with the rotor; a drive train from the drive member to the wheels for synchronous rotation of the wheels on the underwater pool surfaces; a cam having portions of greater and lesser radii, the cam being rotatably secured to the body and driven by the rotor through reduction gearing; and a linkage from the cam to one of the wheels to periodically interrupt the synchronous rotation of the wheels on the pool surface and thereby change the direction of pool cleaner movement.
The water conduit transmitting water to the venturi jets is fed by a flexible hose which is attached in fluid-flow relation to an upstream end of the conduit hose. Water is supplied under pressure from a remote pump through the hose, through a rotatable cylindrical sleeve mount on the housing, in well-known fashion.
In preferred embodiments, there are a plurality of spaced venturi jets. Multiple jets improve the venturi action which draws water and debris from near the underwater surfaces of the pool into the pool cleanerxe2x80x94and ultimately into a filter attached to the pool cleaner. The presence of two or three venturi jets is preferred, and the spacing not only provides more venturi action but serves to provide space to facilitate flow of debris into the inlet. At least one of the venturi jets is preferably oriented toward the outlet to provide an accelerated flow of water directly toward the outlet. Preferred embodiments of this invention include a debris-capturing bag secured to the outlet.
The improved pressure cleaner of this invention provides excellent power and drive particularly when the turbine is in the highly preferred forms which are the subject of U.S. Pat. No. 6,292,970, entitled xe2x80x9cTurbine-Driven Automatic Swimming Pool Cleaners,xe2x80x9d to Dieter J. Rief and Manuela Rief, the inventors herein, and Rosemarie Rief.
In such preferred form, the turbine vanes have proximal ends connected to the rotor and distal ends movable with respect to the rotor between extended positions adjacent to the wall of the turbine chamber and retracted positions which are spaced from the wall and closer to the rotor. Preferably, the turbine vanes are pivotably mounted with respect to the rotor, and most preferably the turbine vanes are curved and have distal edges which contact the chamber wall in their extended positions, at least in certain positions about the rotor. A preferred form of rotational mounting of the vanes is as follows: The rotor has an exterior surface beneath which, for each vane, there is a corresponding cavity which pivotably holds the proximal end of the vane. Enlargements at the proximal ends of the vanes are sized for free insertion into, and pivotable engagement in, the cavities within the rotor.
Each wheel, of course, has an inward side and an outward side depending upon how it is mounted on the pool cleaner. In preferred embodiments of this invention, the first wheel of the set has radially-spaced primary and secondary wheelgears on its inward side, such wheelgears facing one another, and the second wheel of the set has another primary wheelgear on its inward side, the primary wheelgears on the two wheels being similar to one another. Preferably, the drive train terminates at the first and second wheels in first and second drive pinions, respectively, each engaging the primary wheelgear of the respective wheel; this serves to drive the wheels in the forward direction synchronously, in contact with the underwater pool cleaner surface.
In such embodiments, it is preferred that the wheelgears of the first wheel be concentric, and integrally formed with the first wheel itself. The wheelgear of the second wheel is also preferably integrally formed with the second wheel. Most preferably, the first and second wheels are identical, and therefore interchangeable.
As used herein, the term xe2x80x9cwheelgearxe2x80x9d refers to any gear which is affixed on, or formed as part of, a swimming pool cleaner wheel which contacts the surface of the pool to propel the pool cleaner. Among the wheelgears referred to herein are the aforementioned primary and secondary gears and, as will be seen below, gears referred to as xe2x80x9cfinalxe2x80x9d wheelgears.
In preferred embodiments, the drive member is a drive gear and the drive train includes first and second drive shafts which are journaled with respect to the body and which have proximal and distal ends. In such embodiments, the first and second drive pinions, mentioned above, are driven by the first and second drive shafts, respectively, and the drive train is a gear train from the drive gear to the first and second drive shafts. Preferably, the first and second drive shafts form the first and second drive pinions, respectively, at their distal ends.
The drive train preferably includes a coupler with opposite ends receiving the proximal ends of the first and second drive shafts. The proximal end of the first drive shaft is a ball joint which allows the first drive shaft to be pivoted off-axis. This allows the distal end of the first drive shaft to be moved fore and aft between a driving position in which the first drive pinion engages the primary wheelgear of the first wheel and a steering position in which it engages the secondary wheelgear of the first wheel. This movement, from engagement with a wheelgear in the form of a ring gear (with inwardly-facing teeth) to engagement with a wheelgear having outwardly-facing teeth, causes the first wheel to change its direction of rotationxe2x80x94i.e., to rotate in a direction opposite that of the second wheel. This interrupts the synchronous rotation of the wheels on the pool surface, and causes turning of the pool cleaner.
The rotatable cam (a timing cam) mentioned above serves to provide steering of the pool cleaner; in one way or another it causes interruption of synchronous rotation of the first and second wheels on the pool surfaces. In certain preferred embodiments, the linkage from the cam to the first wheel includes a shift bracket assembly which is slidably held by the body in a position such that the first drive shaft is journaled in it, thereby to allow movement of the distal end of the first drive shaft between driving and steering positions, by movement of the shift bracket assembly.
The cam wheel engages the shift bracket and a spring biases the shift bracket toward the cam wheel, such that the cam wheel, acting through the shift bracket assembly, provides the fore-and-aft movement by alternately (a) holding the distal end of the first drive shaft in the driving position and (b) allowing the distal end of the first drive shaft to move to the steering position by virtue of the action of the spring.
The rotatable cam can interrupt synchronous rotation of the first and second wheels on the pool surfaces in other ways. One example of other forms of interruption involves a temporary lifting of one wheel from the surface of the pool when a cam portion of larger radius (larger than most of such cam) engages the pool surface and props one side of the pool cleaner away from the pool surface. In such example, even though the first and second wheels may continue to turn synchronously, they will not be turning synchronously on the pool surface; synchronous rotation on the pool surface is restored when the cam is no longer lifting one side of the pool cleaner.
In highly preferred embodiments, the wheels have treads with a multiplicity of outwardly extending radial fingers. It is most preferred that a small subset of the radial fingers (extending along a very small sector of the wheel) project radially farther than the other fingers. With this embodiment, if the pool cleaner for any reason is hung up on some obstruction or pool surface feature, the longer treads, when they come around, tend to provide traction for dislodgement purposes.
Certain highly preferred embodiments include a second set of wheels, once again including one wheel on each side of the pool cleaner. The wheels of the second set are preferably aft of the wheels of the first-mentioned set. Each of the wheels of the second set has what is being called a xe2x80x9cfinalxe2x80x9d wheelgear on its outward side. In such embodiments, there is an extended drive train for each of the wheels of the second set, and each such extended drive train includes a transfer shaft journaled with respect to the body, a first transfer pinion engaged with one of the primary wheelgears, and a second transfer pinion engaged with one of the final wheelgears. These extended drive trains serve to impart rotation to the wheels of the second set, having transferred rotational movement from the wheels of the first wheel set. Preferably, each transfer shaft itself forms the first and second transfer pinions at the opposite ends thereof.
In pressure cleaners with more than two wheels, it is preferred that all wheels, including those having xe2x80x9cfinalxe2x80x9d wheelgears on them, have wheelgears integrally formed with the wheel. Most preferably, all four wheels (or whatever number there are greater than two) are identical so that they can be completely interchangeable.
The preferred four-wheel-drive pressure cleaner for swimming pools is among the subjects of PCT Patent Application No. PCT/US00/14771, entitled xe2x80x9cFour-Wheel-Drive Automatic Swimming Pool Cleaner,xe2x80x9d for an invention of Dieter J. Rief and Manuela Rief, the inventors herein.
In certain preferred embodiments, the aforementioned water inlet faces the surface of the pool and the device includes a skirt secured with respect to the body and extending toward the pool surface such that the skirt and the body, together with the pool surface, form a plenum from which water and debris are drawn into the inlet. The skirt is formed of at least one flap member which has upper and lower articulating portions, the upper articulating portion having a proximal edge hinged to the body and a lower edge hinged to the lower articulating portion. Most preferably, the skirt is segmented in that it is formed of a plurality of the articulated flap members in side-by-side arrangement, each having upper and lower articulating portions.
Such skirt, which is the subject of commonly-owned copending U.S. Pat. No. 6,131,227, entitled xe2x80x9cSuction-Regulating Skirt for Automated Swimming Pool Cleaner Heads,xe2x80x9d to Dieter J. Rief, an inventor herein, and Hans Raines Schlitzer, facilitates relative enclosure of the plenum despite encountered irregularities in the pool surface immediately under the pool cleaner. As water is drawn into the turbine chamber through the inlet, the skirt minimizes the openness between the pool cleaner body and the underwater surface of the pool, and this causes a speed-up in the linear flow of water immediately along the underwater surface of the pool, at positions under the pool cleaner. Such speed-up of linear flow improves the ability of the pool cleaner to ingest debris along with water, so that the debris tends to move easily into the turbine chamber, and from there through the outlet and into a bag or other collector.